Allow relative symlinks in xbps-alternatives.

bin/xbps-create/xbps-create.1

@@ -83,6 +83,10 @@ A list of required shared libraries, separated by whitespaces. Example:
 .It Fl -alternatives Ar list
 A list of alternatives provided by this package, separated by whitespaces. Example:
 .Ar 'group:symlink:target group2:symlink:target' .
+If
+.Em symlink
+is a relative path, the symlink will be created relative to
+.Em target .
 .El
 .Sh SEE ALSO
 .Xr xbps-checkvers 1 ,

lib/package_alternatives.c

@@ -28,6 +28,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <libgen.h>
 
 #include "xbps_api_impl.h"
 
@@ -39,9 +40,6 @@
  * These functions implement the alternatives framework.
  */
 
-/*
- * XXX TODO: relative symlinks.
- */
 static char *
 left(const char *str)
 {
@@ -74,7 +72,18 @@ remove_symlinks(struct xbps_handle *xhp, xbps_array_t a, const char *grname)
 		str = xbps_array_get(a, i);
 		l = left(xbps_string_cstring_nocopy(str));
 		assert(l);
-		lnk = xbps_xasprintf("%s%s", xhp->rootdir, l);
+		if (l[0] != '/') {
+			const char *tgt;
+			char *tgt_dup, *tgt_dir;
+			tgt = right(xbps_string_cstring_nocopy(str));
+			tgt_dup = strdup(tgt);
+			assert(tgt_dup);
+			tgt_dir = dirname(tgt_dup);
+			lnk = xbps_xasprintf("%s%s/%s", xhp->rootdir, tgt_dir, l);
+			free(tgt_dup);
+		} else {
+			lnk = xbps_xasprintf("%s%s", xhp->rootdir, l);
+		}
 		xbps_set_cb_state(xhp, XBPS_STATE_ALTGROUP_LINK_REMOVED, 0, NULL,
 		    "Removing '%s' alternatives group symlink: %s", grname, l);
 		unlink(lnk);
@@ -102,7 +111,16 @@ create_symlinks(struct xbps_handle *xhp, xbps_array_t a, const char *grname)
 		assert(l);
 		tgt = right(xbps_string_cstring_nocopy(str));
 		assert(tgt);
-		lnk = xbps_xasprintf("%s%s", xhp->rootdir, l);
+		if (l[0] != '/') {
+			char *tgt_dup, *tgt_dir;
+			tgt_dup = strdup(tgt);
+			assert(tgt_dup);
+			tgt_dir = dirname(tgt_dup);
+			lnk = xbps_xasprintf("%s%s/%s", xhp->rootdir, tgt_dir, l);
+			free(tgt_dup);
+		} else {
+			lnk = xbps_xasprintf("%s%s", xhp->rootdir, l);
+		}
 		xbps_set_cb_state(xhp, XBPS_STATE_ALTGROUP_LINK_ADDED, 0, NULL,
 		    "Creating '%s' alternatives group symlink: %s -> %s", grname, l, tgt);
 		unlink(lnk);

tests/xbps/xbps-alternatives/main.sh

@@ -28,6 +28,34 @@ register_one_body() {
 	atf_check_equal $rv 0
 }
 
+atf_test_case register_one_relative
+
+register_one_relative_head() {
+	atf_set "descr" "xbps-alternatives: register one pkg wth an alternatives group that has a relative path"
+}
+register_one_relative_body() {
+	mkdir -p repo pkg_A/usr/bin
+	touch pkg_A/usr/bin/fileA
+	cd repo
+	xbps-create -A noarch -n A-1.1_1 -s "A pkg" --alternatives "file:../file:/usr/bin/fileA" ../pkg_A
+	atf_check_equal $? 0
+	xbps-rindex -d -a $PWD/*.xbps
+	atf_check_equal $? 0
+	cd ..
+
+	xbps-install -r root --repository=repo -ydv A
+	atf_check_equal $? 0
+	rv=1
+	if [ -e root/usr/bin/fileA ]; then
+		lnk=$(readlink root/usr/file)
+		if [ "$lnk" = "/usr/bin/fileA" ]; then
+			rv=0
+		fi
+		echo "A lnk: $lnk"
+	fi
+	atf_check_equal $rv 0
+}
+
 atf_test_case register_dups
 
 register_dups_head() {
@@ -119,6 +147,31 @@ unregister_one_body() {
 	atf_check_equal $rv 0
 }
 
+atf_test_case unregister_one_relative
+
+unregister_one_relative_head() {
+	atf_set "descr" "xbps-alternatives: unregister one pkg with an alternatives group that has a relative path"
+}
+unregister_one_relative_body() {
+	mkdir -p repo pkg_A/usr/bin
+	touch pkg_A/usr/bin/fileA
+	cd repo
+	xbps-create -A noarch -n A-1.1_1 -s "A pkg" --alternatives "file:file:/usr/bin/fileA" ../pkg_A
+	atf_check_equal $? 0
+	xbps-rindex -d -a $PWD/*.xbps
+	atf_check_equal $? 0
+	cd ..
+
+	xbps-install -r root --repository=repo -ydv A
+	atf_check_equal $? 0
+	xbps-remove -r root -yvd A
+	rv=1
+	if [ ! -L root/usr/bin/file -a ! -e root/usr/bin/fileA ]; then
+		rv=0
+	fi
+	atf_check_equal $rv 0
+}
+
 atf_test_case unregister_multi
 
 unregister_multi_head() {
@@ -286,9 +339,11 @@ set_pkg_group_body() {
 
 atf_init_test_cases() {
 	atf_add_test_case register_one
+	atf_add_test_case register_one_relative
 	atf_add_test_case register_dups
 	atf_add_test_case register_multi
 	atf_add_test_case unregister_one
+	atf_add_test_case unregister_one_relative
 	atf_add_test_case unregister_multi
 	atf_add_test_case set_pkg
 	atf_add_test_case set_pkg_group